posted April 26, 2001 12:08 PM
I am wondering as this is my first (4 wheel, also) ABS equipped car- what if anything happens to the ABS system calibration and function if I switch the tire diameter by fiddling with the aspect ratio and width ? I understand the philosophy of ABS is to monitor wheel rotation speed and any wheel rapidly decelerating toward ZERO RPM is a wheel thats about to skid, thus telling the system to release its brake(s) slightly.... So, this RPM 'sampling' the system does, is that RELATIVE to other wheel(s) speed or what I wonder ? If the comparison is versus other wheel's RPM (speed) -then the tire diameter (I'm talking 27.0 OD versus 28.4" OD -or plus 5%) matters not- its all relative isn't it ?

posted April 28, 2001 02:50 PM
as I have been told the factory sets the ABS for minor variations of up to 10% and still performs fine. I think a 5% change in overall tire diameter will not adversely affect the efficiency of your ABS. If you are wanting expert advice, then you better pose this question to a technician at your local dealership.